MARINETTE – Standing by the dark gray hull of the future USS Milwaukee, a Wisconsin senator said kinks are being worked out of the Littoral Combat Ship program in light of two critical federal audits and it continues to move forward.

U.S. Sen. Tammy Baldwin, D-Madison, on Tuesday visited Marinette Marine Corp. where the Lockheed Martin version of the Littoral Combat Ship is being built.

The Littoral Combat Ship program includes two versions of the vessel. The program has been under scrutiny in recent years, including a pair of congressional reports issued last month that noted concerns about the ships' maintenance reliability, crew training and annual operating costs..

"Every prototype ... has to be tested and fully vetted," Baldwin said Tuesday. "That's exactly what's happening. It happens with every new ship, every new procurement, the defense department does. This is no exception."

Work on five of ships is underway at Marinette Marine as some in Washington probe the program and performance of the vessels.

"This shipyard has learned from its prototypes, changed accordingly, and is now getting into the mode of serial production of a ship that incorporates a lot of lessons learned along the way," Baldwin said.

Marinette Marine Corp. is building the Lockheed Martin version of the ship while Austal USA is building a different design of the vessel in Alabama. Marinette Marine already has delivered a pair of ships — the USS Freedom and USS Fort Worth — to the Navy.

Five ships are under construction in Marinette with work expected to start on a sixth this year. The Navy has provided funding for an additional two ships.

Lockheed Martin says the average cost per ship across the first 10 is $360 million each, about half the cost of the first ship in the class – the USS Freedom. Both Lockheed Martin and Marinette Marine say streamlined production and supply processes have helped reduce the per ship cost.

Baldwin said the shipyard in making a "pivot" from prototype and early production ships to producing multiple ships at the same time. Her visit offered an opportunity to look at the ships as she continues to push for full funding of the program in Washington, D.C.

"This ship replaces what might have been done by three different ships," she said. "It is forward thinking when we look at the types of threats we expect in the future."

A pair of reports issued by the independent Government Accountability Office in July raised concerns over the operating costs of the ships as well as the performance on some vessels due to weight increases.

Lockheed Martin say the weight issues related primarily to USS Freedom and has been addressed in subsequent ships.

Earlier this year, Secretary of Defense Chuck Hagel called for a re-evaluation of ship designs and called for a reduction in planned purchases of the ships from 52 to 32.

Area lawmakers, including Baldwin and Republican U.S. Rep. Reid Ribble of Sherwood, have called for continued funding of the program, citing the need for this kind of ship in the fleet and the number of jobs it supports in Wisconsin and Michigan's Upper Peninsula.

The Littoral Combat ship is designed to be a fast warship optimized to carry out a number of missions — including surface warfare and anti-submarine operations — in shallower coastal waters.